1,901 research outputs found
An ecophysiological approach to crop losses exemplified in the system wheat, leaf rust, and glume blotch
No full textThe motive of the author to embark upon the research reported here was the need to develop new concepts to approach the problem of crop losses, and eventually the problem of their prevention by means of disease control and plant breeding. The introduction of ecophysiology as an approach, explained above, was the first result. An ecophysiological treatment of processes like growth and development of plants in health and disease necessitates adjustments of current thoughts on experimental techniques and on organization in research (Van der Wal and Cowan, 1974).In order to measure plant or aegricorpus responses concurrently with environmental factors in climate chamber and field experiments during periods Of months, a great variety of instruments had to be bought, modified, or devised. The climate chamber had to be adjusted to allow for high light intensities with a view to growing wheat under conditions approximating those of early summer in the Netherlands; the yield of the spring wheat 'Kolibri' was c. 0.5 kg.m -2, which is nearly equivalent to the average field production of the country. Regulations for the prevention and control of contamination by aphids and mildew without any use of chemicals were issued after detailed experimentation (Van der Wal, unpubl.). Several instruments have been developed, usually with the help of others; this has led to two publications (Schurer and Van der Wal, 1972; Tegelaar and Van der Wal, 1974). These efforts resulted in the experimental designs described in the appendix. Field experiments, conducted in the same period as the climate chamber experiments reported here, will be published later. It is felt that the techniques to record growth of pathogens are still inadequate.The results reported in the appendix show that the 'state' of the plant at the time of infection is a major determinant of the plant's future behaviour, which plant breeders and pathologists can express in terms of resistance and tolerance. The conceptual framework presented above may contribute to a future revision of crop husbandry and crop protection practices
P.P. van S., De Seldsaame en Noit Gehoorde Wal-Vis-Vangst, Voorgevallen by St. Anna-Land in't jaar 1682 (1684)
No full textDiplomatische weergave van: De Seldsaame en Noit Gehoorde Wal-Vis-Vangst, Voorgevallen by St. Anna-Land in’t jaar 1682. den 7. October. Midsgaders, Een Pertinente Beschrijvinge, Van de geheele Groen-Landse-Vaart. Verhandeld in Prose, en Versen. (...). Door P: P: v: S. Med schoone Kop're Prentverbeeldingen vercierd. Dese 2de. Druk, merkelijk verbetert, en, bij na de helft, vermeerdert. Tot Leiden. in't Jaar 1684
Data with "Shellfish reefs increase water storage capacity on intertidal flats over extensive spatial scales"
No full textDataset in support of the publication "Shellfish reefs increase water storage capacity on intertidal flats over extensive spatial scales" published in Ecosystems, bij Nieuwhof, Van Belzen, Oteman, van de Koppel, Herman and van der Wal. It includes the data and scripts (R and matlab) for the analyses and figures in this publication. This includes aerial images and elevation maps of the 3 shellfish reefs studied and calculated water storage capacity of the reefs. It also includes a map of water storage capacity of the Dutch Wadden Sea south of the island of Schiermonnikoog based on a bathymetry map
Antarctic ice sheet and oceanographic response to eccentricity forcing during the early Miocene
No full textStable isotope records of benthic foraminifera from ODP Site 1264 in the southeastern Atlantic Ocean are presented which resolve the latest Oligocene to early Miocene (~24–19 Ma) climate changes at high temporal resolution (<3 kyr). Using an inverse modelling technique, we decomposed the oxygen isotope record into temperature and ice volume and found that the Antarctic ice sheet expanded episodically during the declining phase of the long-term (~400 kyr) eccentricity cycle and subsequent low short-term (~100 kyr) eccentricity cycle. The largest glaciations are separated by multiple long-term eccentricity cycles, indicating the involvement of a non-linear response mechanism. Our modelling results suggest that during the largest (Mi-1) event, Antarctic ice sheet volume expanded up to its present-day configuration. In addition, we found that distinct ~100 kyr variability occurs during the termination phases of the major Antarctic glaciations, suggesting that climate and ice-sheet response was more susceptible to short-term eccentricity forcing at these times. During two of these termination-phases, ?18O bottom water gradients in the Atlantic ceased to exist, indicating a direct link between global climate, enhanced ice-sheet instability and major oceanographic reorganisations
The influence of the renewed supervising system of the Dutch Inspectorate of Education on teacher autonomy, protocolization and perceived educational quality
No full textThe Dutch Inspectorate of Education has recently (2017) launched a new supervising system to evaluate the educational quality of secondary schools in the Netherlands. In this new system, a division is made between principle-based regulation and rule-based regulation. The aim of this study was to examine 1) whether the type of regulation has an effect on teacher autonomy, 2) whether protocolization has a negative effect on teacher autonomy, 3) whether the type of regulation has an effect on protocolization, 4) whether protocolization is a mediator in the relationship between the type of regulation and teacher autonomy, and 5) whether teacher autonomy has a positive effect on perceived educational quality. Survey analyses demonstrated that a) the type of regulation has an effect on teacher autonomy, b) protocolization has a negative effect on teacher autonomy, c) the type of regulation does not have an effect on protocolization, d) protocolization is not a mediator in the relationship between the type of regulation and teacher autonomy, and e) teacher autonomy does not have an effect on perceived educational quality (although a positive effect for the principle-based regulated schools was found). Practical implications and suggestions for future research are discussed
Carbon nanoparticles in lateral flow methods to detect genes encoding virulence factors of Shiga toxin-producing Escherichia coli
No full textThe use of carbon nanoparticles is shown for the detection and identification of different Shiga toxin-producing Escherichia coli virulence factors (vt1, vt2, eae and ehxA) and a 16S control (specific for E. coli) based on the use of lateral flow strips (nucleic acid lateral flow immunoassay, NALFIA). Prior to the detection with NALFIA, a rapid amplification method with tagged primers was applied. In the evaluation of the optimised NALFIA strips, no cross-reactivity was found for any of the antibodies used. The limit of detection was higher than for quantitative PCR (q-PCR), in most cases between 10 4 and 10 5 colony forming units/mL or 0.1-0.9 ng/¿L DNA. NALFIA strips were applied to 48 isolates from cattle faeces, and results were compared to those achieved by q-PCR. E. coli virulence factors identified by NALFIA were in very good agreement with those observed in q-PCR, showing in most cases sensitivity and specificity values of 1.0 and an almost perfect agreement between both methods (kappa coefficient larger than 0.9). The results demonstrate that the screening method developed is reliable, cost-effective and user-friendly, and that the procedure is fast as the total time required is <1 h, which includes amplification. © 2010 The Author(s).This work was partially supported by the Generalitat Valenciana (BEST/2009/026), the Universidad Politecnica de Valencia (PAID-00-09-2837), and by the Dutch Ministry of Agriculture, Nature and Food Quality (KennisBasis 6 programme). The authors would like to thank Dr. Eva Moller Nielsen at the Danish Veterinary Institute (Copenhagen, Denmark) for providing E. coli control strains and Dr. Lutz Geue (Friedrich-Loeffler-Institut, Wusterhausen, Germany) and Dr. Dorte Dopfer (School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA) for field isolates.Noguera Murray, PS.; Posthuma-Trumpie, G.; Van Tuil, M.; Van Der Wal, F.; De Boer, A.; Moers, A.; Van Amerongen, A. (2011). Carbon nanoparticles in lateral flow methods to detect genes encoding virulence factors of Shiga toxin-producing Escherichia coli. Analytical and Bioanalytical Chemistry. 399:831-838. https://doi.org/10.1007/s00216-010-4334-zS831838399Alocilja EC, Radke SM (2003) Biosens Bioelectron 18:841–846Lazcka O, Campo FJD, Muñoz FX (2007) Biosens Bioelectron 22:1205–1217Nataro JP, Kaper JB (1998) Clin Microbiol Rev 11:142–201Meng J, Doyle MP (1998) Bull Inst Pasteur 96:151–163Karmali MA, Gannon V, Sargeant JM (2010) Vet Microbiol 140:360–370de Boer E, Beumer RR (1999) Int J Food Microbiol 50:119–130Ivnitski D, Abdel-Hamid I, Atanasov P, Wilkins E (1999) Biosens Bioelectron 14:599–624Tokarskyy O, Marshall DL (2008) Food Microbiol 25:1–12Chemburu S, Wilkins E, Abdel-Hamid I (2005) Biosens Bioelectron 21:491–499Rule G, Montagna R, Durst R (1996) Clin Chem 42:1206–1209Ngom B, Guo Y, Wang X, Bi D (2010) Anal Bioanal Chem 397:1113–1135Posthuma-Trumpie GA, Korf J, van Amerongen A (2009) Anal Bioanal Chem 393:569–582Carter DJ, Cary RB (2007) Nucleic Acids Res 35:e74Kalogianni DP, Goura S, Aletras AJ, Christopoulos TK, Chanos MG, Christofidou M, Skoutelis A, Ioannou PC, Panagiotopoulos E (2007) Anal Biochem 361:169–175Litos IK, Ioannou PC, Christopoulos TK, Traeger-Synodinos J, Kanavakis E (2009) Biosens Bioelectron 24:3135–3139Blažková M, Koets M, Rauch P, van Amerongen A (2009) Eur Food Res Technol 229:867–874Mens PF, van Amerongen A, Sawa P, Kager PA, Schallig HD (2008) Diagn Microbiol Infect Dis 61:421–427Gordon J, Michel G (2008) Clin Chem 54:1250–1251Aldus CF, van Amerongen A, Ariens RM, Peck MW, Wichers JH, Wyatt GM (2003) J Appl Microbiol 95:380–389Capps KL, McLaughlin EM, Murray AW, Aldus CF, Wyatt GM, Peck MW, van Amerongen A, Ariens RM, Wichers JH, Baylis CL, Wareing DR, Bolton FJ (2004) J AOAC Int 87:68–77van Amerongen A, Koets M (2005) In: van Amerongen A, Barug D, Lauwaars M (eds) Rapid methods for biological and chemical contaminants in food and feed. Wageningen Academic Publishers, Wageningen, pp 105–216Moreira BG, You Y, Behlke MA, Owczarzy R (2005) Biochem Biophys Res Commun 327:473–484Nielsen EM, Andersen MT (2003) J Clin Microbiol 41:2884–2893Huijsdens XW, Linskens RK, Mak M, Meuwissen SGM, Vandenbroucke-Grauls CMJE, Savelkoul PHM (2002) J Clin Microbiol 40:4423–4427Koets M, Sander I, Bogdanovic J, Doekes G, van Amerongen A (2006) J Environ Monit 8:942–946van Amerongen A, Wichers JH, Berendsen LBJM, Timmermans AJM, Keizer GD, van Doorn AWJ, Bantjes A, van Gelder WMJ (1993) J Biotechnol 30:185–195O’Keeffe M, Crabbe P, Salden M, Wichers J, van Peteghem C, Kohen F, Pieraccini G, Moneti G (2003) J Immunol Methods 278:117–126Posthuma-Trumpie GA, Korf J, van Amerongen A (2008) Anal Bioanal Chem 392:1215–1223Chang LL, Shepherd D, Sun J, Ouellette D, Grant KL, Tang XC, Pikal MJ (2005) J Pharm Sci 94:1427–1444Geue L, Segura-Alvarez M, Conraths FJ, Kuczius T, Bockemuhl J, Karch H, Gallien P (2002) Epidemiol Infect 129:173–185Eurachem/CITAC (2003) EURACHEM/CITAC Guide: The expression of uncertainty in qualitative testing. LGC, Teddington, Middlesex, UK, p 22Ellison SLR, Fearn T (2005) Trac-Trends Anal Chem 24:468–476Gilchrist JM (2009) J Clin Microbiol 62:1045–1053Landis JR, Koch GG (1977) Biometrics 33:159–174Mackinnon A (2000) Comput Biol Med 30:127–134Mil’man BL, Konopel’ko LA (2004) J Anal Chem 59:1128–1141AOAC (2006) Final report and executive summaries from the AOAC International Presidential Task Force on best practices in microbiological methodology. AOAC International, Gaithersburg, Maryland, USA, p 20
Verstuiving van suppletiezand; Den Helder 1996; inventarisatie van de situatie voor suppletie.
No full text
- …
